Generally, in various electronic devices or electrical devices such as mobile phones, a terminal part of each of various signal transmission media composed of, for example, thin coaxial cables, flexible wiring boards, or printed wiring boards has been commonly connected to a printed wiring board side by using an electrical connector (for example, see below-described Patent Literature 1). The electrical connector connects the terminal part of the signal transmission medium to a predetermined wiring pattern (circuit). Normally, for example as shown in FIG. 11, a receptacle connector 3 is mounted on a circuit board 2 attached to an inner part of a product chassis 1, and a plug connector 5, which is coupled to a terminal part of a signal transmission medium 4 composed of a thin coaxial cable or the like, is configured to be mated with the receptacle connector 3. The functions of the electrical connectors 3 and 5 used in this case are to carry out transmission of necessary information signals through signal lines and to connect a shield signal for grounding to a ground circuit through a shield line.
On the other hand, recently, reduction in size/thickness of electronic devices, etc. have been rapidly developed, and the height and cost of electrical connectors have been accordingly reduced. Therefore, simplifying the above described configuration of the electrical connectors 3 and 5 has been strongly required. In order to omit the receptacle connector 3, it is conceivable to directly solder a connection leg part of the plug connector 5 to an electrically conductive path on the product chassis 1. However, since the product chassis 1 is made of a resin molding material, the chassis has low thermal resistance, and this state does not allow direct soldering or mounting of an electronic part to the product chassis. Therefore, all of normally-used electrical connectors have a basic configuration that one of the electrical connectors (receptacle connector) 3 is mounted on the printed wiring board 2 having a wiring pattern and the other electrical connector (plug connector) 5 is in a state mated therewith. Due to restrictions of such a basic configuration, it is becoming difficult to significantly reduce the height and cost.